Calculate subnets, IP ranges, CIDR notation, and network details
Enter an IP address and click Calculate
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Subnet Calculator is a free online tool for network administrators and engineers to calculate IP subnet details. Enter an IP address with CIDR notation or subnet mask to get network address, broadcast address, usable host range, and total number of hosts. Essential for network planning and IP address management.
Our calculator supports IPv4 subnetting and provides detailed breakdowns of network classes, wildcard masks, and binary representations for educational purposes.
Calculate subnets using CIDR notation (/24, /16, etc.) or traditional subnet masks.
Get the first and last usable IP addresses in any subnet instantly.
See binary representations to understand how subnetting works.
Plan network segmentation with accurate host counts and address ranges.
CIDR (Classless Inter-Domain Routing) notation represents IP addresses with their subnet mask as a suffix. For example, 192.168.1.0/24 means the first 24 bits are the network portion, leaving 8 bits for hosts (254 usable addresses).
A /24 network has 256 total addresses (2^8), but only 254 are usable for hosts. The network address and broadcast address are reserved, leaving 254 addresses for devices.
A subnet mask divides an IP address into network and host portions. Common masks include 255.255.255.0 (/24) for 254 hosts and 255.255.0.0 (/16) for 65,534 hosts.